This disclosure relates to an audio device with a loudspeaker
Intermodulation distortion (IMD) in an acoustic cavity can limit how loud a headset can be played. IMD can occur when relatively large transducer excursions cause the motor force constant to vary, leading to undesired frequency components. Off-ear headphones, where the acoustic radiators are held close to but not on or in the ears, are generally driven at higher amplitude in order to provide desired sound levels to the ears. IMD can become a greater problem at higher amplitude. IMD thus can be a particular problem for off-ear headphones.